Question

A resistor develops 300 J of thermal energy in 15 s, when a current of 2 A is passed through it. If the current increases to 3 A, the energy developed in 10 s is ______ J.

Answer 1

We know that,
$H = i^2Rt$
$300 = 22 \times R \times 15$
$R = \frac {300}{4\times15}$
$R = 5\ Ω$
Now,
Energy developed $=I_2^2Rt^2$
$= 9 × 5 × 10$
$= 450\ J$

So, the answer is $450\ J$.